1. Field of the Invention
This invention relates to a thin film magnetic head comprising a slider supported by a substrate and a thin film magnetic head supported by the substrate and to a method for manufacturing the same.
2. Related Art Statement
Conventionally, a thin film magnetic head, comprising a first magnetic member including a first pole portion and a first yoke portion, a second magnetic member including a second pole portion opposing to the first pole portion via a write gap film and constituting an air bearing surface opposing to a magnetic recording medium with the first pole portion and a second yoke portion magnetically connected to the first yoke portion in the remote position from the air bearing surface, a thin film coil of which part enclosed by the first and second magnetic members, a coil support-insulating film, and a protection film, is known.
In manufacturing such a thin film magnetic head, generally, a second magnetic film which is to be a top magnetic film is formed after a first magnetic film (bottom magnetic film), a write gap film, an insulating film to support a thin film coil are formed on a wafer. In forming the second magnetic film, a plate-underfilm for the second magnetic film is formed entirely over the wafer including the insulating film by sputtering, for example. Next, a photoresist is applied on the plate-underfilm, and is etched by photolithogrphy to form a resistframe for the second magnetic film. Subsequently, in the area enclosed by the resistframe is formed the second magnetic film by electroplating or the like. A plate film is also deposited outside the resistframe, but is removed later.
One of the problems in the forming process of the second magnetic film is that in the photolithography process to form the resistframe, an exposing light is reflected at the surface of the insulating film and the reflected light exposes the photoresist beyond the area to be defined by a photomask, resulting in the degradation of the pattern precision of the resist frame and thereby the degradation of the pattern precision of the second magnetic film.
The problem become conspicuous in the pole portion of the second magnetic film. The pole portion of the second magnetic film is opposed to the first magnetic film via the write gap film. Backward from the pole portion is positioned the insulating film, which rises up on the write gap film with inclined at a given angle. The rising start point is called as a xe2x80x9cthroat height zero pointxe2x80x9d, and the rising angle is called as an xe2x80x9capex anglexe2x80x9d.
The second magnetic film is formed so as to constitute the pole portion parallel to the write gap film and the first magnetic film up to the throat height zero point and be inclined at the apex angle toward the upper surface of the insulating film from the throat height zero point.
Thus, in forming the resist frame for the second magnetic film, the photoresist stuck on the inclined part at the apex angle toward the upper surface of the insulating film from the throat height zero point must be exposed.
In this case, since the plated underfilm is stuck on the inclined part, the light for expose is reflected at the plated underfilm. The part of the reflected light goes toward the pole portion. Thus, the exposed pattern of the pole portion is different from the exposing pattern of the photomask, resulting in the pattern destruction of the resist frame corresponding to the pole portion.
The pattern destruction of the resist frame is a large obstacle for realizing a high recording density by narrowing a recording track width up to 1.0 xcexcm and below, for example.
Kokai publication Kokai Hei 9-180127 (JP A 9-1880127) discloses the technique that before applying a photoresist as a mask for a top magnetic film, an antireflection film is formed, and on the antireflection film is applied a photoresist, which is exposed and developed, to form a resistframe as a mask for a second magnetic film. After forming the resist frame, the antireflection film is removed by ashing or the like and the second magnetic film is formed by plating or the like.
In the above conventional technique, the antireflection film exists over the interior pattern enclosed by the resistframe. The interior pattern of the resistframe has a pole portion area corresponding to the pole portion of the top magnetic film and a second yoke portion corresponding to the yoke portion thereof. Thus, the antireflection film must be removed from both the pole portion area and the second yoke portion.
However, the opening area in the pole portion area is remarkably different from that in the second yoke portion. Moreover, for attaining a high density recording, the opening area of the pole portion area is inclined to be narrowed to a minute size of 1 xcexcm and below, for example. Thus, in removing the antireflection film stuck on the interior pattern enclosed by the resist frame, the etching rate of the second yoke portion is different from that of the pole portion area and it takes longer time in etching the pole portion area than the second yoke portion. As a result, during the removing the antireflection film from the pole portion area, the resist frame is remarkably etched, resulting in the broadening of the resist frame. That is, the removing process of the anti-reflection film to narrow the pole portion width enlarges the space of the resistframe. As a result, the antireflection film impedes to narrow the pole portion width.
It is an object of the present invention to provide a thin film magnetic head comprising a second magnetic member having a second pole portion formed in a high precise pattern without the pattern deviation due to an undesired reflection of an exposing light in photolithography.
It is another object of the present invention to provide a thin film magnetic having a narrowed recording track width.
It is still another object of the present invention to provide a method for manufacturing the above thin film magnetic head effectively.
This invention relates to a thin film magnetic head including a slider composed of a substrate and a thin film magnetic head element supported by the substrate, the thin film magnetic head element comprising
a first magnetic member including a first pole portion and a first yoke portion,
a second magnetic member including a second pole portion opposing to the first pole portion via a write gap film and constituting, with the first pole portion, an air bearing surface to oppose to a magnetic recording medium, and a second yoke portion magnetically connected to the first yoke portion in the remote position from the air bearing surface,
a thin film coil of which part is surrounded by the first and second magnetic members,
a coil support-insulating film to support the thin film coil,
a throat height zero point-defining insulating film rising on the write gap film so as to define the throat height zero point, and
an antireflection film between the rising-inclined portion of the throat height zero point-defining insulating film and the second pole portion of the second magnetic member.
This invention also relates to a method for manufacturing a thin film magnetic head including a slider composed of a substrate and a thin film magnetic head element supported by the substrate, the thin film magnetic head element having a first magnetic member including a first pole portion and a first yoke portion, a second magnetic member including a second pole portion opposing to the first pole portion via a write gap film and constituting, with the first pole portion, an air bearing surface to oppose to a magnetic recording medium and a second yoke portion magnetically connected to the first yoke portion in the remote position from the air bearing surface, a thin film coil of which part is surrounded by the first and second magnetic members, a coil support-insulating film to support the thin film coil, and an antireflection film between the coil support-insulating film and the second pole portion of the second magnetic member, comprising the steps of:
forming the antireflection film on the surface of the coil support-insulating film including an inclined portion rising on the write gap film after forming the first magnetic member, the write gap film, the thin film coil and the coil support-insulating film and before forming the second magnetic member,
patterning the antireflection film by a photolithography process so that the patterned antireflection film can remain only on the inclined portion,
applying a photoresist so as to cover the antireflection film and the coil support-insulating film,
forming a resistframe having a given enclosed pattern through a photo-lithography process for the photoresist to form the second magnetic member, and
forming the second magnetic member in the enclosed pattern of the resistframe so as to cover the antireflection film.
This invention further relates to a method for manufacturing a thin film magnetic head including a slider composed of a substrate and a thin film magnetic head element supported by the substrate, the thin film magnetic head element having a first magnetic member including a first pole portion and a first yoke portion, a second magnetic member including a second pole portion opposing to the first pole portion via a write gap film and constituting, with the first pole portion, an air bearing surface to oppose to a magnetic recording medium and a second yoke portion magnetically connected to the first yoke portion in the remote position from the air bearing surface, a thin film coil of which part is surrounded by the first and second magnetic members, a coil support-insulating film to support the thin film coil, a throat height zero point-defining insulating film rising from the write gap film so as to define the throat height zero point, and an antireflection film between the throat height zero point-defining insulating film and the second pole portion of the second magnetic member, comprising the steps of:
forming the throat height zero point-defining insulating film on the write gap film so that its edge in the side of the air bearing surface can define the throat height zero point after forming the first magnetic member and the write gap film and before forming the thin film coil, the coil support-insulating film and the second magnetic member,
forming the antireflection film so as to cover the throat height zero point-defining insulating film,
patterning the antireflection film by a photolithography process so that the patterned antireflection film can remain only on the inclined portion of the throat height zero point-defining insulating film in the side of the air bearing surface,
applying a photoresist so as to cover the antireflection film,
forming a resistframe having a given enclosed pattern through a photolithography for the photoresisit to form the second pole portion,
forming the thin film coil so as to be supported by the coil support-insulating film, and
forming the magnetic film constituting the second yoke portion of the second magnetic member on the coil support-insulating film so as to be connected to the second pole portion.
In the manufacturing method of a thin film magnetic head, the magnetic film constituting the second yoke portion is preferably formed so that its edge in the side of the air bearing surface may be receded from the air bearing surface.
Although in a normal thin film magnetic head, the antireflection film is removed from the complete thin film magnetic head so as not to remain therein, in the thin film magnetic head of the present invention, the antireflection film is not removed and remains therein. The remaining antireflection film give various advantages as follows:
First of all, since the antireflection film is provided on the rising inclined portion of the thin film coil support-insulating film or the throat height zero-defining insulating film, the exposing light is almost never reflected at the inclined portion in forming the resistframe by the photolithography for forming the second pole portion of the second magnetic member. Accordingly, the exposed pattern of the photoresist to define the shape of the second pole portion of the second magnetic member is almost determined by the exposing pattern of the photomask, particularly, so that the pattern of the resistframe corresponding to the second pole portion can be formed high precisely. That is, according to the present invention, the second pole portion can be formed in a high precise pattern. Moreover, since the pattern of the resistframe corresponding to the second pole portion is prepared high precisely, the thin film magnetic head having a narrowed recording track width can be manufactured.
Furthermore, different from the conventional manufacturing method, it is not required to remove the antireflection film, which does not result in the degradation of the pattern precision of the resistframe due to the difference in etching rate between the second yoke portion and the second pole portion and the decrease of the resistframe height, etc. Therefore, the second pole portion and the second yoke portion can be formed in a high precise pattern.
Moreover, since the antireflection film is covered with the second magnetic member, the remaining antireflection film does not influence the thin film magnetic head as a final product.